1. Field of the Disclosure
The technology of the disclosure relates to terminating fiber optic mechanical splice connectors to an optical fiber, and more particularly, to a splice connector installation tool and fiber optic mechanical splice connectors containing stub optical fibers.
2. Technical Background
Optical fibers are useful in a wide variety of applications, including the telecommunications industry. Optical fibers can be employed for voice, data and video transmissions. With the ever increasing and varied use of optical fibers, apparatus and methods have been developed for coupling optical fibers to one another outside a controlled environment of a factory setting, commonly referred to as “field installation” or “in the field.” Examples of “field installations” include a telephone central office, an office building, and outside plant terminals. In order to efficiently couple optical signals transmitted by the optical fibers, a fiber optic connector must not significantly attenuate, reflect, or otherwise alter the optical signals. In addition, fiber optic connectors for coupling optical fibers must be relatively rugged and adapted to be connected and disconnected a number of times in order to accommodate changes such as moves, adds or changes in the optical transmission path that may occur over time.
Although fiber optic connectors are efficiently and reliably mounted upon the end portion of an optical fiber in a factory setting, it is often desirable to install fiber optic connectors in the field. In other words, the end user can install the fiber optic connector on the end portion of an optical fiber in the field. Installing fiber optic connectors in the field can advantageously minimize cable lengths and optimize cable management and routing. In this regard, installation tools have been developed to facilitate the splice termination of one or more optical fibers to a fiber optic connector, and particularly, to enable the splice termination of one or more field optical fibers to a mechanical splice connector. Examples of conventional installation tools for performing mechanical splices in the field are described in U.S. Pat. Nos. 5,040,867; 5,261,020; 6,816,661; and 6,931,193. In particular, U.S. Pat. Nos. 6,816,661 and 6,931,193 describe a UNICAM® installation tool available from Corning Cable Systems LLC of Hickory, N.C., designed specifically to facilitate mounting the UNICAM® family of fiber optic connectors upon the end portions of one or more field optical fibers.
FIGS. 1A and 1B respectively illustrate an exemplary field-installable, mechanical splice fiber optic connector 10 (also referred to as “mechanical splice connector” and “fiber optic connector 10”) suitable for use with the installation tool before and after termination. The fiber optic connector 10 may be a member of the UNICAM® family of mechanical splice connectors. As shown in FIGS. 1A and 1B, the mechanical splice connector 10 includes a connector ferrule 12 defining a lengthwise, longitudinal bore for receiving and securing a stub optical fiber 14 in a known manner, such as by an adhesive. The forward end 16 (also referred to herein as the “end face”) of the ferrule 12 is typically precision polished such that the stub optical fiber 14 is flush with (as shown) or slightly protruding from the end face 16 of the ferrule 12. The rear end 18 of the ferrule 12 is inserted into and secured within the forward end of a ferrule holder 20 so that the stub optical fiber 14 extends rearwardly a predetermined distance from the ferrule 12 between a pair of opposed splice components 22, 24 disposed within the ferrule holder 20. In turn, the ferrule holder 20, including the ferrule 12 and splice components 22, 24, are disposed within a connector housing 26.
With continuing reference to FIGS. 1A and 1B, a cam member 28 is movably mounted to the ferrule holder 20 and the connector housing 26 for engaging a keel portion of the lower splice component 24. If desired, the ferrule 12, the ferrule holder 20 and the cam member 28 may be biased relative to the connector housing 26, for example by a coil spring 30, to ensure physical contact between the end face 16 of the ferrule 12 and the end face of an opposing ferrule in a mating fiber optic connector or optical device (not shown). Finally, a spring retainer 32 may be disposed between the connector housing 26 and a medial portion of the cam member 28 and fixed to the connector housing 26 so as to retain one end of the spring 30 relative to the connector housing 26. As a result, the ferrule 12, the ferrule holder 20 and the cam member 28 are biased forwardly, yet permitted to piston rearwardly relative to the connector housing 26.
To make a splice within a connector, a field optical fiber 34 is inserted into a rear end of the ferrule holder 20 opposite the ferrule 12 and the stub optical fiber 14 as illustrated by the horizontal directional arrow AH in FIG. 1A. Typically, the field optical fiber 34 is coated or tight-buffered with a buffer 36 that is stripped back to expose a predetermined length of the end of the field optical fiber 34. The mechanical splice connector 10 may be further provided with a crimp tube 38 including a fiber entry 40. The crimp tube 38 retains and strain relieves the buffer 36 of the field optical fiber 34. With a portion of the buffer 36 removed, the field optical fiber 34 can be inserted and advanced into the rear of the mechanical splice connector 10 between the splice components 22, 24 until the end portion of the field optical fiber 34 makes physical contact with the end portion of the stub optical fiber 14. Thereafter, the cam member 28 is actuated by moving or rotating the cam member 28 relative to the ferrule holder 20 about the longitudinal axis of the connector 10, to engage the keel on the splice component 24 and thereby force the lower splice component 24 in the direction of the upper splice component 22. Movement of the lower splice component 24 causes the end portion of the stub optical fiber 14 and the end portion of the field optical fiber 34 to seat within the V-shaped groove formed in the lower splice component 24, thereby aligning and securing the field optical fiber 34 relative to the stub optical fiber 14 between the splice components. Accordingly, the field optical fiber 34 is optically coupled to the stub optical fiber 14 as a mechanical splice for transmitting an optical signal between the field optical fiber 34 and the stub optical fiber 14.
To make an acceptable mechanical splice, a clean and undamaged optical fiber 34 should be inserted into the fiber optic connector 10 for achieving a satisfactory termination with the stub optical fiber 14 within the connector. A conventional practice is to insert the optical fiber 34 manually within the fiber optic connector 10 in the installation tool by aligning the optical fiber 34 with a crimp tube 38 of the fiber optic connector 10. This conventional practice is generally sufficient for highly-trained and experienced technicians; however, less experience technicians may lack the know-how and/or have difficulty make high-quality terminations in the field. Moreover, the conventional practice typically includes re-cleaving a damaged optical fiber 34 and/or cleaning optical fibers 34 contaminated with debris when the optical fibers 34 are not properly inserted in the fiber optic connector 10 on the first attempt. In other words, depending on the skill, eyesight, and dexterity of the technician, as well as ambient light, alignment and insertion of the optical fiber 34 in the fiber optic connector 10 may require more than one attempt. Consequently, there is an unresolved need for devices and methods that provide high-quality terminations in the field by the technician.